Petróleos Mexicanos, Mexico's state-owned oil company, is preparing to export three tankers to shipbreaking yards in Pakistan, Bangladesh, India or China, where environmental regulations are minimal and often unenforced, according to the Basel Action Network (BAN).

BAN, an organization that works to confront the environmental and social impacts of toxic trade worldwide, has called on the Mexican government to block the export, which it says violates the United Nations Basel Convention, as well as Mexican law.BAN explains the legal issue:

Mexico has implemented the Basel Ban Amendment, which only permits the export of hazardous wastes to OECD countries, EU countries and Liechtenstein. Pakistan, Bangladesh, India and China are non-OECD and therefore cannot legally receive these vessels as waste from Mexico for any reason unless they are first decontaminated of all toxic materials.

The ships, which were all built before 1978, can legally be recycled in Mexico, the U.S. or other developed countries, after being first tested for toxic substances and individual parts recycled accordingly.

BAN says the government has full jurisdiction over what happens to the vessels. The organization hopes that Pemex was simply unaware of the international law it will be violating if it proceeds with the export, and that plans will change as a result of the letter it sent to the government of Mexico.